System.Trunc Function

Truncates a real number to an integer.

Pascal

function Trunc(X: Extended): Int64;

C++

Int64 Trunc(Extended X);

File

System

Description

In Delphi code, the Trunc function truncates a real-type value to an integer-type value. X is a real-type expression. Trunc returns an Int64 value that is the value of X rounded toward zero.

If the truncated value of X is not within the Int64 range, an EInvalidOp exception is raised.

Delphi Examples:

Copy Code

{
This example demonstrates how the Trunc function operates
on various real numbers.
}
procedure TForm1.Button1Click(Sender: TObject);
var
   S, T: string;
begin
   Str(1.4:2:1, T);
   S := T + ' Truncs to ' + IntToStr(Trunc(1.4)) + #13#10;
   Str(1.5:2:1, T);
   S := S + T + ' Truncs to ' + IntToStr(Trunc(1.5)) + #13#10;
   Str(1.6:2:1, T);
   S := S + T + ' Truncs to ' + IntToStr(Trunc(1.6)) + #13#10;
   Str(-1.4:2:1, T);
   S := S + T + ' Truncs to ' + IntToStr(Trunc(-1.4)) + #13#10;
   Str(-1.5:2:1, T);
   S := S + T + ' Truncs to ' + IntToStr(Trunc(-1.5)) + #13#10;
   Str(-1.6:2:1, T);
   S := S + T + ' Truncs to ' + IntToStr(Trunc(-1.6)) + #13#10;
   Str(2.5:2:1, T);
   S := S + T + ' Truncs to ' + IntToStr(Trunc(2.5)) + #13#10;
   Str(-2.5:2:1, T);
   S := S + T + ' Truncs to ' + IntToStr(Trunc(-2.5)) + #13#10;
   Str(-2.6:2:1, T);
   S := S + T + ' Truncs to ' + IntToStr(Trunc(-2.6));
   MessageDlg(S, mtInformation, [mbOk], 0, mbOk);
end;